Change in maternal body mass index is associated with offspring body mass index: a 21-year prospective study.

PURPOSE: To examine whether changes in maternal overweight and obesity from pre-pregnancy to two decades postpartum predict the body mass index (BMI) of adult offspring.

METHODS: We used a subsample of 1997 mother-offspring pairs from the 7,223 original cohorts of women who gave birth in Brisbane, Australia, between 1981 and 1984. Multiple linear regression and multinomial logistic regression were used to examine the relationship between change in maternal BMI from pre-pregnancy to 21-year postpartum, and offspring BMI at 21-year, adjusting for potential confounding factors.

RESULTS: At 21-year postpartum, 31.15 % mothers were overweight and a further 30.80 % were obese. Mothers gained a mean weight of 16.07 kg over the 21 year. We found that the offspring of mothers who became overweight or remained overweight at 21-year postpartum were at greater risk of being overweight and obese at 21 years. In the adjusted model, offspring of mothers who had normal BMI before pregnancy but became overweight by 21-year postpartum were (odds ratio) 1.72 (95 % CI = 1.20, 2.47) times more likely to be overweight. Compared to offspring of mothers who maintained normal weight over two decades, offspring of mothers who remained persistently overweight were (odds ratio) 5.39 (95 % CI = 3.50, 8.30) times more likely to be obese by age 21 year.

CONCLUSIONS: The findings of this study suggest that long-term changes in maternal BMI from pre-pregnancy to 21-year postpartum are independently associated with BMI in their young adult offspring.